A device of the above-mentioned type is described in EP-A-0 707 462. In that device, an endoprosthesis is mounted coaxially on two hollow supports capable of sliding relative to each other. The endoprosthesis is maintained in its retracted state by means of two filamentary connections surrounding it at its ends. The filamentary connections are passed into distal and proximal retention openings, respectively, provided in the one and the other of the supports, respectively. The connections are engaged around a retention rod in order to keep them in position at their proximal end.
In order to release the endoprosthesis, the supports are displaced by sliding relative to each other in such a manner that the distance between the retention openings decreases.
The decrease in this distance brings about the loosening of the filamentary connections and consequently the simultaneous deployment of the two ends of the endoprosthesis.
When the positioning of the endoprosthesis in the blood circulation canal is satisfactory, the rod for retaining the filamentary connections is removed from the device. The filamentary connections are then withdrawn from the supports and removed from the patient's body by causing them to slide in the supports.
Bearing in mind the great length of the filamentary connections, and their winding path in the supports, the risk of the filamentary connections becoming jammed or breaking during their withdrawal is high. The reliability of the device is therefore reduced.